C1q nephropathy among children with nephrotic syndrome: Ten-year experience from a pediatric nephrology unit

Abstract

Abu-Shahin N, Al-Khader A, Qattan D, Akl K. C1q nephropathyamong children with nephrotic syndrome: Ten-year experience from a pediatricnephrology unit. Turk J Pediatr 2018; 60: 14-21.C1q nephropathy (C1qN) is a rare glomerulopathy mostly seen in children,and presents with nephrotic syndrome (NS). Diagnosis depends onimmunoflourescence or immunohistochemical C1q mesangial deposition,excluding other immune-mediated diseases. We retrospectively investigatedC1qN incidence, clinicopathological features, and outcome among pediatric NSin our institution.Clinical data, microscopic slides and corresponding tissueblocks of pediatric renal biopsies were retrieved. According to diagnosticcriteria for C1qN, 53 pediatric NS renal biopsies were selected for AntiC1qA IHC stain microscopic examination. Clinicopathological features andfollow up data were recorded. C1qN incidence was 9.4% among pediatricNS biopsies. Mesangial proliferation was the most common histopathologicalpattern. Steroid dependency with frequent relapses was the most frequentoutcome, with a second line immunosuppressant added, yet without impacton progression. Small sample size hinders coherent conclusions; nevertheless,it indicates that C1qN is a rare cause of pediatric NS. C1qN may requiresecond line immunosupressants more often than non-C1q NS.